INFLUENCE OF WATER ON THE CRISPNESS OF CEREAL-BASED FOODS - ACOUSTIC,MECHANICAL, AND SENSORY STUDIES

The texture properties of crispy breads were studied as a function of water content using compression tests, acoustic measurements and senso ry analysis. The addition of water slowly lowers the characteristics a ssociated with crispness up to 9%, after which they steeply decrease. Dynamic Mechanical Thermal Analysis (DMTA) measurements were carried o ut, at room temperature and at 5 Hz, on the same bread samples. The ev olution of the textural properties of crispy bread are accompanied by an increase of the loss factor prior to the one associated to the glas s transition. It was therefore proposed that the effect of water on th e brittle character, on crispness and on the intensity of the sound em itted at fracture were due to the onset of molecular motions preceding or accompanying The glass transition.